Group details of group services

ABSTRACT

A server for a communication system is disclosed. The server is configured to receive group communication information comprising a group detail indicator. The group detail indicator provides information on at least an identity of a group and a type of the group. The server is further configured to store the group communication information, and to make the group communication information available to predefined entities.

FIELD OF THE INVENTION

The invention relates to communication systems, and more particularly tocommunication systems providing group communication, such as directvoice communication sessions or instant messaging. In particular, theinvention relates to providing information on group details relating togroup communication.

BACKGROUND OF THE INVENTION

A communication system can be seen as a facility that enables groupcommunication between two or more entities such as user terminal and/orother nodes associated with the communication system. Subscribers, suchas the users or end-users, to a communication system may be offered andprovided numerous services, such as calls, data communication ormultimedia services or simply an access to a network, such as theInternet. The services may be offered by an operator of thecommunication system or by an external service provider.

A communication system typically operates in accordance with a givenstandard or specification setting out what the various entitiesassociated with the communication system are permitted to do and howthat should be achieved. A standard or specification may define aspecific set of rules, such as communication protocols and/orparameters, on which connections between the entities can be based.

Examples of communication systems may include fixed line communicationsystems, such as a public switched telephone network (PSTN), wirelesscommunication systems, e.g. global system for mobile communications(GSM), general packet radio service (GPRS), universal mobiletelecommunications system (UMTS), wireless local area network (WLAN) andso on, and/or other communication networks, such as an Internet Protocol(IP) network and/or other packet switched data networks. Variouscommunication systems may simultaneously be concerned in a connection.An end-user may access a communication network by means of anyappropriate communication device, such as user equipment (UE), a mobilestation (MS), a cellular phone, a personal digital assistant (PDA), apersonal computer (PC), or any other equipment operable according to asuitable network protocol, such as a Session Initiation Protocol (SIP)or a wireless applications protocol (WAP) or a hypertext transferprotocol (HTTP). The user equipment may support, in addition to call andnetwork access functions, other services, such as short message service(SMS), multimedia message service (MMS), electronic mail (email), Webservice interface (WSI) messaging and voice mail.

Services offered to subscribers of a communication system may compriseconferencing services, such as multiparty conferencing, for example,so-called direct voice communication services. The direct voicecommunication service may allow users to engage in immediatecommunication with one or more users. One example of the direct voicecommunication services may comprise the “push-to-talk over cellular”(PoC) service also known as the PTT (push-to-talk service). The PoC maybe based on Voice over IP (VOIP) technology in cellular networks, suchas the GSM/GPRS network.

Services offered to subscribers of a communication system may compriseinstant messaging. The instant messaging communication service may allowusers to send messages with one or more users. The instant messagingrefers to the transfer of messages between users in near real-time.These messages are usually, but not required to be, short. Instantmessages are often used in a conversational mode, that is, the transferof messages back and forth is fast enough for participants to maintainan interactive conversation. A sent message may be just a plain text orit may contain some payload such as picture or application.

The direct voice communication services may use capabilities of, forexample, the Internet Protocol Multimedia Subsystem (IMS), which is anexample of a system providing multimedia services. The IMS enables IPconnections for a communication device and other parties to thecommunication, such as other communication devices or entitiesassociated with the network. The third generation partnership project(3GPP) has defined use of the GPRS for offering IP connectivity to IMSservices.

Patent Application U.S. 2002/0150091, filed on 17 Apr. 2001, in the nameof Lopponen et al., discusses about a packet mode, e.g. IP, groupcommunication service layer provided on top of a standard mainstreamcellular network.

US Patent Application, filed on 23 Aug. 2004, claiming priority from Fl20040577 (23 Apr. 2004), in the name of Poikselka et al., discussesabout providing information on a resource in a communication system,such as whether the resource comprises an individual user identity or aplurality of user identities.

Open Mobile Alliance (OMA) OMA-RD_PoC-V1_(—)0-20040628-C, Push to Talkover Cellular Requirements, version 1.0—28 Jun. 2004, defines the PoC,which is based on half-duplex communications. Thus, one user subscribingthe PoC service, i.e. a first PoC subscriber, and belonging to a groupmay speak at the time and the other users, or PoC subscribers, belongingto the group may listen, but may not talk at the same time. The firstPoC subscriber may select a person or groups of persons to talk to, forexample, from a directory or the like provided in a communication devicethe first PoC subscriber is using. The first PoC subscriber may pressand hold a push-to-talk key on the communication device to starttalking. The first PoC subscriber can now talk for as long as the firstPoC subscriber holds the key. The push-to talk key may be a specificbutton, tangent or any other appropriate key in a user interface.Similar principles apply with devices having touch sensitive or soundactivated user interfaces. Bi-directional communication may be offeredsince all parties of the communication session may similarly communicatevoice data with the PoC application server, which is an example of anentity controlling the PoC session. As soon as the first PoC subscriberreleases the push-to-talk key, another member of the group may reserve aturn to speak. A turn to speak may be requested by pressing thepush-to-talk key. The PoC application server or another controllingentity may grant a turn to speak on a first come first served basis orbased on priorities. Talk bursts in the PoC conferences are usuallyconnected without the recipient answering and typically received througha built-in loud speaker of a communication device.

In a group communication, a party which is the target of a connectionattempt, namely the called party or recipient, might need or want toreceive identity of an initiating party, namely the calling useridentity, and also a group identity (group ID) of the group into whichthe called party is intended to participate.

For example, in the PoC system, a PoC client, such as software in acommunication device, may use a group identity for learning ordetermining other members in the group and performing joining the group.

In addition to the group identity, a recipient client may need or wantto learn details on the group. For example, in many group services,there are several types of groups that behave in different manners froma point of view of an end user. For example, theOMA-RD_PoC-V1_(—)0-20040628-C, paragraph 6.1.2 defines following threegroup types: ad-hoc, pre-arranged and chat.

A group, such as an ad-hoc and chat group, may be temporary. Therecipient client should not store a group ID of a temporary group, asthe group ID may not be valid after the session to which the group IDrelates is over. On the other hand, persistent groups also exist,pre-arranged PoC group being an example. A recipient client may store agroup ID of a persistent group for later use, e.g. to initiate a newsession.

It might be advantageous to a recipient client to learn the group type.For example, the recipient client might thus be able to decide whetherthe group ID should or need to be stored and how the group ID may beused.

So-called Industry Consortium Specifications [Push-To-Talk over Cellular(PoC); Signaling Flows—UE to Network Interface (UNI) and Push-To-Talkover Cellular (PoC) Signalling Flow—Network-to.Network interface (NNI);PoC Release 2.0] use a “From” to transport the calling party identitywhen the talk session is an instant personal talk or an ad-hoc instantgroup talk. When the talk session is an instant group talk or a chatgroup talk then a “From” header transports the group identity of thegroup. A “Referred-By” header is used to transport the calling partyaddress in case of an instant group talk or to a chat group talk. Theproblem in this approach may be that a recipient cannot trust toinformation given in the “From” header, as a sending client or end usermay be able to fill the “From” header freely without a SessionInitiation Protocol (SIP) network, such as IMS, validating the “From”header. Also, use of the “Referred-by” header outside of the context ofa REFER method may be against SIP principles.

It shall be appreciated that these issues are not limited to anyparticular communication environment, but may occur in any appropriatecommunication system.

SUMMARY OF THE INVENTION

Embodiments of the invention aim to address one or several of the aboveproblems or issues.

In accordance with an aspect of the invention, there is provided aserver for a communication system. The server is configured to receivegroup communication information comprising a group detail indicator,wherein the group detail indicator provides information on at least anidentity of a group and a type of the group. The server is furtherconfigured to store the group communication information. The server isfurther configured to make available the group communication informationto predefined entities.

In accordance with another aspect of the invention, there is provided acommunication device. The communication device comprises memory meansfor storing a group detail indicator wherein the group detail indicatorprovides information on at least an identity of a group and a type ofthe group. The communication device further comprises uploading meansfor uploading the group detail indicator to a server. The communicationdevice further comprises downloading means for downloading the groupdetail indicator for storing the group detail indicator to the memorymeans.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in further detail, by way of exampleonly, with reference to the following examples and accompanying drawing,in which:

FIG. 1 shows an example of an arrangement in which the embodiments ofthe invention may be implemented; and

FIG. 2 shows an example of a further arrangement in which theembodiments of the invention may be implemented.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows an example of an arrangement including a communicationnetwork 10 providing group services, a first communication device 12, asecond communication device 14, a third second communication device 16and a fourth second communication device 18, each of said communicationdevices 12, 14, 16, 18 capable of using group services.

A user of a communication device, for example the first communicationdevice 12, may participate in group communication with another groupuser, for example a user using the second communication device 14. In analternative, a user of a communication device, for example the firstcommunication device 12, may participate in group communication with agroup, for example with a group comprising the second communicationdevice 14 and the third communication device 16. A user may participatein more than one group at a time. A user may receive notifications ofgroups available to participate in and may request to join those groups.A user may also receive invitations to participate in groups.

Furthermore, a group communication server 20 is shown in FIG. 1. Thegroup communication server 20 is an entity controlling groupcommunication and supporting creation and management of group lists.Operation of the exemplifying group communication server shall becomeillustrated in the following description.

It shall be appreciated that FIG. 1 is only an example showing fourindividual devices and one group communication server. The number andtype of these entities may differ substantially from that which isshown. A communication system is typically arranged to serve a pluralityof communication devices. The group communication may comprise groupcommunication sessions, such as conferencing sessions, and instantmessaging. In an embodiment, the group services comprise PoC services.In an embodiment, the communication network 10 shown in FIG. 1 is asession initiation protocol (SIP) controlled network. Further, in anembodiment, the communication network 10 is provided at least in part bythe Internet multimedia subsystem (IMS). In an embodiment, a generalpacket radio service (GPRS) based system is used as a backbonecommunication network enabling the IMS services. Another appropriatemobile communication system may be used as well.

A mobile communication network may logically be divided into a radioaccess network (RAN) and a core network. The core network entitiestypically include various control entities and gateways for enablingcommunication via a number of radio access networks and also forinterfacing a single communication system with one or more communicationsystems, such as with other cellular systems and/or fixed linecommunication systems.

The IMS, among other systems, may use the Session Initiation Protocol(SIP), which is an application layer control protocol defined by theInternet Engineering Task Force (IETF) for creating, modifying andterminating sessions with one or more participants. The SIP is definedin the document IETF RFC 3261 “SIP: Session Initiation Protocol”. A userconnected to a SIP base communication system may communicate withvarious entities of the communication system based on standardized SIPmessages. Communication devices or user who run certain applications onthe communication devices are registered with the SIP backbone so thatan invitation to a particular session can be correctly delivered tothese end points. The SIP provides a registration mechanism for devicesand users and it applies mechanisms such as location servers andregistrars to route the session invitations appropriately.

Uniform Resource Identifiers (URIs) are used to identify different typesof actors in a SIP-controlled network. Typically a URI points to aregistered user identity of an individual user. A URI may identify alsoservices, such as voicemail server or conference factory URI,conferencing instances, such as chat rooms or voice-over-IP (VoIP)conferencing instances, or other types of resources. In addition, a URImay point to a resource list, which may be a list of individual URIs, orin other words, a group of URIs. Resource lists may be used in manyapplications, such as for one-to-many messaging, and so on. For example,a server in a network may maintain resource lists of e.g. one operator.A request addressed to such a resource list may be routed to the server,which may forward the request to individual contacts behind the resourcelist.

In this specification, terms user, end-user, user agent, subscriber andresource all refer to an entity able to using services via acommunication network. A user or user agent is typically an individualregistered user identity. Term end-user may be used to denote a humanuser of the system. A subscriber or resource may refer to an individualuser or to a group of users subscribing a single subscription. Termsresource list and group define herein an entity having an ownidentifier, such as an own URI, and comprising a number of entities eachhaving a different identifier, such as a different URI.

As explained above, a recipient client may need or want to know a grouptype in addition to a group identity. Three exemplifying group typeswere mentioned: ad-hoc, pre-arranged and chat group. Group types mayfurther comprise one-to-one (1-to-1) type and other defined or undefinedtypes. A group of communication devices for multiparty conferencing,such as the PoC, can be created in various ways. For example, the SIP ora conference policy control protocol (CPCP) may be used.

An ad-hoc group is temporary. The recipient client should not store agroup ID of an ad-hoc group, as the group ID is not valid after thegroup communication to which the group ID relates is over. An ad-hocgroup communication may be established when a first PoC subscriberselects more than one other PoC subscribers and invites them toparticipate in an ad-hoc group communication. Voice communication may bestarted after one other PoC subscriber the first PoC subscriber invited,i.e. a second PoC subscriber, accepts the invitation. To participate inan existing ad-hoc PoC group session, a new participant typically needsan invitation from a current ad-hoc PoC group session participant. Anexception is that a PoC subscriber, who was a participant of the ad-hocgroup session, but left the session, may join in again without aninvitation. In such a case, the group ID may need to be storedtemporarily.

A chat PoC group session is established when a first PoC subscriberjoins in. Voice communication is possible at the time the chat PoC groupsession is established. A PoC subscriber may establish a chat PoC groupsession or join into an ongoing chat PoC group session.

On the other hand, a pre-arranged group is persistent. A recipientclient may store a group ID of a pre-arranged group for later use, e.g.to initiate a new group communication. Participation in a pre-arrangedgroup is restricted to the members of the group. The members may beinvited to a pre-arranged PoC group session or may join an ongoingsession. A PoC session between pre-arranged PoC group members may beestablished when any individual member of the same pre-arranged PoCgroup invites the group. Voice communication may be started after oneother PoC subscriber the first PoC subscriber invited, i.e. a second PoCsubscriber, accepts the invitation.

Embodiments of the present invention provide new alternatives forinforming group details, including at least a group identity and grouptype, to a called party in a group communication. In an embodiment,other type of information may additionally be provided.

The group communication server 20 shown in FIG. 1 may be used forimplementing embodiments of the invention. The group communicationsserver 20 may comprise information on groups relating to or capable ofhaving a group communication session or capable of instant messaging.Such information may be illustrated by means of a group table 30 asshown in FIG. 1. The group table may identify a group, for example, bymeans of a group URI 32. Each group URI 32 may comprise a number ofmembers 34. A type 36 of the group, for example pre-arranged, ad-hoc,chat, 1-to-1 or other, is defined.

Furthermore, a manipulation interface 40 is shown in FIG. 1. Themanipulation interface may allow a user to create and manage grouplists, for example, using a communication device or a web page. Forexample, the user may determine a pre-arranged group to be stored in thegroup table 30.

In embodiments of the invention at least one request to initiate groupcommunication comprising a group detail indicator is created. The groupdetail indicator provides information on at least an identity of a groupof communication devices and a type of the group. The group detailindicator is provided to at least one communication device of the group.In an embodiment, a request to initiate the group communication, orshortly an originating request, may be received in a server, e.g. acontrolling server, or other such entity. The originating request may bereceived from an originating or initiating party, such as acommunication device wishing to initiate group communication. The serveror other such entity may create the at least one request to initiate thegroup communication comprising the group detail indicator using theoriginating request the entity received from the initiating party. In anembodiment, the entity may detect that the originating request relatesto a group and determine the type of the group.

Examples of group communication servers may comprise, but are notlimited to, a PoC server or a PoC service enabler and a conferenceserver. A network may comprise a separate element for storing andmanaging contact lists, group lists and access lists. Examples of suchelements may comprise, but are not limited to, a Group/List ManagerServer (GLMS) and an Extensible Mark-up Language (XML) DocumentManagement Server (XDMS). A group communication server 20 may retrievegroup lists (including group type) from separate elements, such as GLMSand XDMS. The type of the group may define a type of the groupcommunication server storing information relating to the group. Forexample, a PoC server may store application specific group lists, suchas ad-hoc conference URIs and members created by the CPCP. An XMDS maystore general URI lists which may be shared by multiple applications,for example. In an embodiment, the server controlling the groupcommunication may be able to determine the type of the group usinginformation on a lifetime of the group or configured information at theserver.

XML Document Management (XDM) is a generic framework for group and listmanagement called based on XML Configuration Access Protocol (XCAP). TheXDM defines a common mechanism that makes information accessible to thedifferent enablers that need them. The information is expected to bestored in the network. In the network, the information may be located,accessed and manipulated, e.g. created, changed and deleted, byauthorised principals. A client may be able to identify elements insideone XML document and modify only the elements needed to be modified.

An URI list may be shared between multiple enablers. For example, aprincipal may group together a number of end users, e.g. “Friends” or“Family”, or other resources. Such an URI list may be reused by a numberof different enablers, such as PoC and Presence service enablers.

FIG. 2 shows and exemplifying XDM architecture as defined in Open MobileAlliance, Group Management Architecture, Draft Version 1.0—18 Nov. 2004,OMA-PAG-GM-AD-V1_(—)0-20041118-D. Main components of the XDMarchitecture may comprise an XDM client 202, an aggregation proxy 204,application servers 210, 211, 212 and XDM Servers (XDMS) 220, 221, 222,225. The aggregation proxy 204 acts as contact point for XCAP requestsfrom a XDM client 202. The aggregation proxy 204 may authenticate androute the requests to a correct XDMS 220, 221, 222, 225.

A PoC XDMS 222 may contain PoC access policy documents and PoC groupdocuments. Each PoC user may have one access policy document, which maybe used for controlling incoming PoC session invitations. PoC groupdocuments may be used to control group sessions. A presence XDMS 220 maycontain authorization policy documents, which may be used to authorizewatcher subscribing presence information. Furthermore, the presence XDMS220 may contain resource list server (RLS) presence list documents,which may be used to subscribe with one request presence of listedusers.

The XDM client 202 may store URI lists to the shared XDMS 225, which maybe then shared between multiple applications. Client may create a sharedURI list to the shared XDMS 225 and add to a PoC group document areference to the shared URI list. The shared URI list in the shared XDMS225 can be used as member list of a group. The same shared URI list canbe referenced also from an RLS document. In addition, the shared XDMS225 can be used to share URI lists (contact information) betweenmultiple devices hold by the same user. For example, when the user takesa new device into use, the new device may receive service settings, forexample, Over-the-air. Subsequently, all the information stored in localXDM servers is available to the new device. Thus, the information storedinto the local XDM servers does not need other synchronizationmechanisms to be synchronized between the devices owned by the user.

The shared URI list may be an XML document. The XDM client 202 maymanipulate an XML document by invoking predefined HTTP operations on anXDM server identified in a Request-URI of an HTTP header. The XDM client202 may construct the Request-URI based on application usage knowledgegoverning said XML document. Examples of manipulating XML documents aregiven in Open Mobile Alliance, PoC XDM Specification, Draft Version1.0—19 Jan. 2005, OMA-TS-PoC_XDM-V1_(—)0-20050119-D, Appendix B,paragraph B.1.

A user or an application server 210, 211, 212 can subscribe to changesin the XML documents. A SIP URI of an owner of the shared URI list or bya public service identity (PSI) URI of the group associated with theshared URI list may be used fro subscribing.

Information relating to groups is shown in a form of a group table inFIG. 1. However, a group table is only an illustrating example. Thegroup communication server 20 may use various ways of handling datarelating to groups, for example directories, lists, additional serversand so on. Typically, a group communication server 20 handles aplurality of groups at a time. The communication network 10 may comprisemultiple group service providers each having one or more groupcommunication servers.

In an embodiment, a new URI parameter, in addition to the group identitycarried by the URI, may be defined for transporting the group type. Thisnew URI parameter may be named, for example, a group type parameter.According to this embodiment, the group type parameter may be added inthe end of a URI in appropriate SIP message header(s), such as theContact, To, From or P-Asserted-Id header, to indicate the type of thegroup to which the URI points.

A new URI parameter according to an embodiment of the invention may bedefined, for example, in one of the following ways: Header: <group-URI;group=grouptype>; or Header: <group-URI>; group=grouptype

where the “group-URI” denotes a base uniform resource identifierproviding the identity of the group and the “group” denotes the new URIparameter according to an embodiment of the invention, wherein the“grouptype” gets a value of the type of the group, e.g. chat, ad-hoc,pre-arranged, 1-1, other. Any other words or text string or combinationof characters or bit string could be used instead of “group” or“grouptype” to achieve the intended function.

An example of a new URI parameter according to an embodiment of theinvention may comprise: Contact: <sip:myfriends@example.com;group=pre-arranged>; or Contact: <sip:myfriends@example.com>;group=pre-arranged

In a similar manner the group type may be defined as a new headerparameter or attached to any existing SIP header.

In an embodiment, a new SIP header may be defined for transporting thegroup details. RFC 3261, paragraph 7.3 defines the SIP header fields.Each header field consists of a field name followed by a colon and thefield value. The format of a header field-value is defined perheader-name, which may be text or a combination of whitespace, tokens,separators, and quoted strings.

A new SIP header, which may be denoted by “Group-ID” or any otherselected word or text string or combination of characters or bit string,according to an embodiment of the invention may be defined, for example,in the following way: Group-id: group-URI; group-type

where the “group-URI” field contains the group identity, such as a SIPURI (session initiation protocol uniform resource identifier) or TEL URI(telephony uniform resource identifier) identifying the group, e.g.myfriends@example.com. In an embodiment, it may be possible to transportalso a display name associated to the group identity. The “group-type”field contains the type of group, e.g. chat, ad-hoc, pre-arranged,1-to-1, other.

An example of a new SIP header according to an embodiment of theinvention may comprise: Group-id: “Miikka's friends”<sip:myfriends@example.com>; pre-arranged

In an embodiment, the SIP header may also be a so-called private SIPheader. In this embodiment, the syntax of the SIP header may beP-Group-id: group-URI; group-type

In a further embodiment, the group details may be transported in anextended mark-up language (XML) payload. TheOMA-RD_PoC-V1_(—)0-20040628-C, e.g. paragraph 6.2.1, defines a groupadvertisement (GA) operation. The GA may be used to advertise existenceof group to recipients. The GA is a stand-alone operation, which doesnot initiate communication other than transferring the groupadvertisement itself. A structure of the GA may carry the group ID (SIPor TEL URI) and the group type. In an embodiment of the invention, adata structure carrying the group detail indicator, namely the group IDand the group type, in an extended mark-up language payload attached toa request to initiate a group communication session, is used to make therecipient client aware of the group details in the received groupsession or message. The request to initiate the group communicationsession may comprise an invitation request or a stand-alone message ofthe session initiation protocol, i.e. both SIP INVITE and MESSAGE.

An example of an XML payload according to an embodiment of the inventionmay comprise: Content-Type: application/vnd.poc.groupdetails+xmlContent-Length: 151 <?xml version=“1.0” encoding=“UTF-8”?> <group><uri>sip:group.uri@domain.net</uri> <name>Group Display Name</name><type>pre-arranged</type> </group>

A Session Description Protocol (SDP) is a session description protocolfor multimedia sessions defined, for example, in the document IETF RFC2327 “SDP: Session Description Protocol”. The SDP may be used forcommunicating existence of a session and conveying sufficientinformation to enable joining and participating in the session. The SDPmay include session name and purpose, time(s) the session is active, themedia comprising the session and information to receive those media(addresses, ports, formats and so on) and, optionally, information aboutthe bandwidth to be used by the conference and contact information forthe person responsible for the session.

In a further embodiment of the invention, a new SDP attribute may bedefined for transporting the group details. Such a new SDP attribute maybe named a group ID SDP attribute and may have the following form:a=poc-group-id: group URI; group type group URI = SIP URI or TEL URI ofthe group group type = ad-hoc, pre-arranged, chat, 1-1, other

An example of a new SDP attibute may comprise: a=poc-group-id:myfriends@example.com; pre-arranged

In the following, examples are described on the use of a group detailindication according to embodiments of the invention. A controlling PoCserver is a server, which knows or is able to retrieve a type of a groupand is able to insert it to outgoing requests.

In an embodiment, Alice wants to create an ad-hoc group. She sends anINVITE request to her PoC server. The request contains other users to beinvited. Alice's PoC server will take the role of controlling PoCserver. The controlling PoC server thus knows that Alice wants to createan ad-hoc group. The controlling PoC server uses a list of usersprovided in the request to invite said users. When the controlling PoCserver invites other members using SIP INVITE, the controlling PoCserver includes information about the group identity (SIP URI) and thegroup type. Eventually, the request is received by the invited users,i.e. called parties. When a PoC client of a called party receives therequest, the PoC client could display to an end-user that the incomingsession is an ad-hoc group session, as the request contains the type ofsession, and further that the initiator is Alice. Moreover, as therequest contained the group identity, the PoC client is able to makesubscription to the participant information.

In another embodiment, Alice wants to reach members of pre-arrangedgroup. She sends an INVITE request to her PoC server. The requestcontains the address of pre-arranged group. The request is routed to aPoC server hosting the pre-arranged group. The PoC server hosting thepre-arraged group will fetch the members of the pre-arranged group andinvites the other members than Alice. The PoC server hosting thepre-arranged group Will take the role of a controlling PoC server. Whenthe controlling PoC server invites other members using SIP INVITE thecontrolling PoC server includes information about the group identity(SIP URI) and the group type. Eventually, the request is received by theinvited users, i.e. called parties. When a PoC client of a called partyreceives the request, the PoC client could display to an end-user thatthe incoming session is from a pre-arranged group, as the requestcontains the type of session, and further that the initiator is Alice.Moreover, as the request contained the group identity, the PoC client isable to make subscription to the participant information.

A communication device, such as User Equipment (UE), of a user mayimplement additional features utilising the group type indication toimprove the user-friendliness of the UE. Examples of such features maycomprise for example following situations. In an embodiment, if a usertries to store in a phonebook of the UE a SIP URI, which is an “ad hoc”type of SIP URI, the UE may tip the user off about the SIP URI being atemporary address by displaying a warning. Furthermore, the UE may askwhether the user really wants to store said SIP URI in the phonebook. Inan embodiment, the group type may be stored in a phonebook of the UE.

Further, a user may miss a call, for example, because the user didn'thear the phone ringing. The user might also miss an invitation to agroup session. When the user next time checks the UE, the user can seeall the missed calls in a so-called missed call log of the phone. Thismakes it easy to call back to missed numbers. In an embodiment, if themissed call was an invitation to a group session, the group type mayalso be seen in the missed call log.

In an embodiment, the UE may display group type information to a userwhen the UE receives a session invitation. This allows for instance todistinct 1-1 calls from group calls. Moreover, the user may havedifferent ringing tones or handling for different kind of sessions.

For example, a user may receive an invitation request from the networkbut does not answer. Later, when the user checks the UE, the user maynote that a call has been missed and may attempt to call back. Knowingthat a URI to be invited is a pre-arranged group type the UE of a usermay warn the user when the user dials the pre-arranged group identity.This may be advantageous, as the pre-arranged group identity triggers 1to N new calls in the server and may cause significant charges for theuser.

In a further example, a group, e.g. myfriends@example, may compriseusers A, B, C, D and E. The user A may send a request to initiate agroup communication, such as a SIP MESSAGE, to the group. The user B mayget information that the request was sent by the user A and that thegroup in question is a pre-arranged group. Thus, the user B knows thatcalling said group triggers 1 to N new calls in the server and may causesignificant charges for the user.

A user can receive address of the group in the group advertisement (GA).The user may save the address of the group locally to a communicationdevice the user is using. It has now been found that the address of thegroup should be able to be saved also to a network server, such as theshared XDMS 225. The user may thus be able to share address of the groupamong multiple devices. This may be advantageous when user wants tochange the communication device or use several devices simultaneously.

In an embodiment, the group type parameter according to the invention isbe added to the shared XDMS 225 of FIG. 2. This allows saving alsogroups to the shared XDMS 225 and separating a group URI from a SIP URI,which defines only a single SIP user instead of group.

In an embodiment, user may save a received group URI to the shared XDMS225. In the shared XDMS 225, the group type parameter according to theinvention is used to differentiate a group URI from an URI pointing toan individual contact. To maintain the very same information betweenphonebook applications of two devices, such as an original device andthe new device, all the information included to the GA may be stored tothe shared XDMS 225.

An illustrating, non-limiting example of the above embodiment is givenin the following. For example, Joe receives a GA from his friend Bob:“Hi, please use this Group (sip:golf_buddies@example.com) forcommunicating with our golf friends, all others have already joined tothis group”. The group type parameter according to the inventionincluded in the GA may show that the group type is Chat. Joe may savethe received Group URI and group type from the GA to a communicationdevice Joe is currently using and additionally to the shared XDMS 225.When Joe buys a new communication device, he may want to download allhis personal contacts of individual user, such as sip:bob@example.com,and used groups, such as sip:golf_buddies@example.com, to the newcommunication device. When Joe is able to use the information stored inthe XDMS 225, the information may be downloaded without creating thisinformation manually to the new communication device.

In a further embodiment, a user, who is called John herein, may create alocal ad-hoc group containing three other users and store the ad-hocgroup into a phonebook application of a communication device John iscurrently using. The ad-hoc group is now persistent, since the ad-hocgroup was stored to the phonebook application. However, the ad-hoc groupis private, because only John is aware of an existence of the ad-hocgroup and able to use information of the ad-hoc group. In order to beable to synchronize this kind of ad-hoc groups between separate devicesJohn uses, John may store the group to the shared XDMS 225. The sharedXDM data format is extended to contain the group type attached to thelist name using the group type parameter according to the invention.Referring to this exemplifying case, the shared XDMS 225 may store alist name, such as <mybuddies>, and the group-type, such as “ad-hoc”,attached to the list name and under the list name, the members (displayname and URI) of the list.

In order to initiate sessions or send messages towards to an ad-hocgroup as defined in the previous example, an initial SIP request may beable to refer to the list stored in the shared XDMS 225.

Embodiments of the invention may at least partially be realized inappropriate network elements by means of a computer program. Thecomputer program may comprise program code means for performing stepsaccording to said embodiments when the program is run on a computingmeans.

Although the invention has been described in the context of particularembodiments, various modifications are possible without departing fromthe scope and spirit of the invention as defined by the appended claims.It should be appreciated that whilst embodiments of the presentinvention have mainly been described in relation to mobile communicationdevices such as mobile stations, embodiments of the present inventionmay be applicable to other types of communication devices that mayaccess communication networks providing direct voice communicationservices. Furthermore, the communication system may be any appropriatecommunication system, even if reference has mainly been made to mobilecommunication systems.

1. A server for a communication system, the server being configured to:receive group communication information comprising a group detailindicator, wherein the group detail indicator provides information on atleast an identity of a group and a type of the group; store the groupcommunication information; and make available the group communicationinformation to predefined entities.
 2. The server according to claim 1,further configured to allow the predefined entities to perform at leastof manipulation, uploading and downloading the group communicationinformation.
 3. A server for a communication system, the servercomprising: a receiver for receiving group communication informationcomprising a group detail indicator, wherein the group detail indicatorprovides information on at least an identity of a group and a type ofthe group; a memory for storing the group communication information; andan interface for making available the group communication information topredefined entities.
 4. The server according to claim 3, comprising oneof a shared document management server and an extendible mark-uplanguage document server.
 5. A communication device comprising: memorymeans for storing a group detail indicator wherein the group detailindicator provides information on at least an identity of a group and atype of the group; uploading means for uploading the group detailindicator to a server; and downloading means for downloading the groupdetail indicator for storing the group detail indicator to the memorymeans.
 6. A communication device configured to: store a group detailindicator wherein the group detail indicator provides information on atleast an identity of a group and a type of the group; upload the groupdetail indicator to a server; and download the group detail indicatorfor storing the group detail indicator to a memory means.
 7. Thecommunication device according to claim 6, further configured to receivethe group detail indicator in a message from a network.
 8. Thecommunication device according to claim 7, wherein said messagecomprises one of a request to initiate said group communication and agroup advertisement.
 9. A method for indicating group detail informationrelating to group communication in a communication system, the methodcomprising: attaching a reference to a request to initiate said groupcommunication, wherein said reference is referring to a list stored in aserver in a network, the list comprising a group detail indicatorproviding information on at least an identity of a group and a type ofthe group.
 10. A computer program embodied on a computer readablemedium, the computer program comprising program code means forindicating group detail information relating to group communication in acommunication system, wherein the computer program performs the step of:attaching a reference to a request to initiate said group communication,wherein said reference is referring to a list stored in a server in anetwork, the list comprising a group detail indicator providinginformation on at least an identity of a group and a type of the group.